Measurement of Activity Coefficients at Infinite Dilution Using Gas−Liquid Chromatography. 6. Results for Systems Exhibiting Gas−Liquid Interface Adsorption with 1-Octanol

Abstract

Activity coefficients at infinite dilution provide a useful tool for solvent selection in extractive distillation or extraction processes. In this work activity coefficients at infinite dilution for various solutes (alkanes, cycloalkanes, alcohols, aromatic hydrocarbons, xylenes and alkenes) in the solvent 1-octanol were measured at four temperatures, (293.44, 303.45, 313.55, and 323.43) K, with the help of gas-liquid chromatography. The adsorption at the gas-liquid interface between the solutes and the solvent was examined by varying the solvent liquid loading in the columns. Corrected retention values taking adsorption effects into account are determined and are used to calculate the activity coefficients at infinite dilution. These values compare well with various activity coefficients taken from the literature using different techniques and the predicted values using the modified UNIFAC (Dortmund) method. An important application of the present data can be seen in the use of 1-octanol as a solvent for processes such as extractive distillation or extraction. It is sufficient to know the separation factor at infinite dilution of the components to be separated in order to determine the applicability of 1-octanol as a selective solvent.

Comparison of two simulation methods to compute solvation free energies and partition coefficients

“…Generally, there is also reasonable agreement with experimental data. [57–69] The results for the solvation free energies in 1‐octanol, shown in Table 2, by the two calculation methods are also close to each other and to the experimental data. The standard deviations for the EE and TI methods are also within ±0.03 kJ/mol.…”

“…[58] and calculated from experimental liquid‐ and gas‐phase molar concentration taken from Refs. [60–64].…”

“…The calculated hydration and 1‐octanol solvation free energies are also compared with available experimental data[57–64] in the Tables 1 and 2. Table 3 gives a comparison between the calculated 1‐octanol/water partition coefficients reported here with the experimental data.…”

Systems with ionic liquids: Measurement of VLE and γ∞ data and prediction of their thermodynamic behavior using original UNIFAC, mod. UNIFAC(Do) and COSMO-RS(Ol)

“…The evaluation procedure for the measurement of c 1 i with the g.l.c. apparatus was discussed by Gruber et al [12].…”

Predicting infinite dilution activity coefficients of hydrocarbons in water using ant colony optimization

“…The most important methods are: gas-liquid chromatography (GLC), non-steady-state gas-liquid chromatography, differential ebulliometry, static methods and the dilutor method [3,4,[8][9][10][11]. For reasons of time, cost, safety and technical availability, it is necessary to predict ∞ rather than to measure it.…”